Paving streets



(No Model.) v

I P. GRIFFIN.

PAVING STREETS.

No. 430,013. PatentedJune'lo, 1800.

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UNITED STATES PATENT OFFICE.

PATRICK GRIFFIN, OF UTIO, NEIV YORK.

PAVING STREETS.

SPECIFICATION forming part of Letters Patent No. 430,013, dated J' une10, 1890.

`Application filed December 3, i889. Serial No. 332,373. (No model.)

To all whom it may concern:

Be it known that I, PATRICK GRIFFIN, residing at Utica, in the county ofOneida and State of New York, have invented certain new and usefulImprovements in Paving Streets, of which the following is aspecification, reference being had therein to the accompanying drawings.

This invention relates to paving or roadconstruction for streets andhighways.

The object of the invention is to produce a .protected pavement orroadway, wherein the natural soil shall be a very prominent constituent,but which shall have many of the wearing qualities of a concrete orasphaltcovered pavement and greater elasticity than the common varietiesof concrete.

To carry out my invention in constructing a roadway, I eXcavate or llalong the line of the road until the proposed surface-level isapproximated. If filling has to be done to any considerable extent, theearth used in lling should be compacted-as by rolling or ramming-untilsuch a compactness is had that there will be little or no subsequentsettling. In cuts or where the natural surfacelevel is used the naturalearth will answer for` a foundation, if it be not boggy. Havingapproximated the desired level or grade, I apply to the entire surfaceof the roadway a body of clayor loam in convex form, the crown or centerof the street being some inches higher than the sides. Where the earthin situ is a clay or clay-loam, it may be simply turned up and rounded,so that the crown will be higher than the sides ot' the road. If thesoil is very largely composed of clean or sharp sand, the surface may beremoved and some six or eight inches of clay or clayey soil will besubstituted. At the sides of the road-bed it is desirable to have gooddrainage. The drainage may be effected by va gutter or by sunken tile ora sewer or other usual means of draining. The clay or earth for theroadway, if dry, should be moistened or wet to a proper consistencysufficiently to insure its packing. The rounded or'convexbody of clay inmoistened condition is then firmly compacted by rolling, ramming,

or in other suitable manner until it is extremely solid, like anartificial stone, care being observed to preserve the convexity'andsmoothness of the compacted clay surface. I prefer to compact the clayby rolling, and have devised a roller for the purpose, by which verygreat pressure may be applied,

and have applied for a patent on said roller. p

Having brought the clay to a state of eX- treme solidity, as abovedescribed, if there be a surplus of moisture the same may be removed bythe artificial application of heat. Thus the surface may be rolled withhot rollers, or a pan filled with burning combustibles may be drawn overthe surface, or a jet of heated air may be blown on the clay surface.The moisture in the upper layer can thus be entirely removed, and thewhole surface of the clay may be brought to the consistency of apartially burned brick. Having compacted and dried the clay, and whileit is in a dry state, a wearing-surface of asphalt or other water-proofmaterial-suoli as is used in concrete pavements-is applied to thecompacted clay road-bed. This asphalt coating is preferably applied intwo layers, each layer being of about an inch in thickness, and bypreference the upper and lower layers of the concrete are separated, sothat the upper layer may be removed and replaced in making repairswithout disturbing the lower layer.

Referring now to the drawings, Figure l is a cross-sectional viewintended to illustrate a roadway constructed after the manner of thisinvention. Fig. 2 is a plan of a short section of a roadway, showingcompacting and drying apparatus. Fig. 3 is a cross-section of a part ofthel clay bed of the road and a drying and heating apparatus thereon.

A indicates the earth-stratain natural condition. If the soil be wet, itmay be drained by any required number of under drains, as indicated at BB.

C indicates a side drain for the roadway. This may be of tile, brick,rough or broken stone, or even poles laid in a blind ditch, the objectbeing to convey away any superfluous moisture from the compacted part ofthe roadbed.

D denotes the sewer, which when laid with proper relation to the roadwaywill obviate the necessity of a side drain. (In sandy soil, or wherethere is considerable slope to the ICO road or street, side drains orsewers are sometimes necessary.)

E represents the body of compacted clay or loam. The upper convexsurface of this body of earthy matter is compacted to a condition ofextreme hardness and made dry.

F indicates the lower, and G the upper, layer of rock or other asphaltor water-proof coating, which makes a water-proof covering to thecompact clay road-bed. The layers are preferably made so that the upperone G may be removed Without disturbing the lower one.

In Fig. 2, R represents a roller, and S a drying pan or kiln, resting onthe clay body E of the road-bed. The drying pan or kiln may be drawnabout on runners s s,with its lower heated metallic surface just abovethe road-bed. Numerous other devices for compactin g and drying the claybed may be used.

I give these merely as examples. The asphalt covering F G is applied inthe manner usual in surfacing streets. The compacted and dried claybecomes almost like brick, and will not resume its original conditioneven if exposed to water for a very long time. It is my object, however,to keep it perfectly dry by means of the water-proof covering. rlheartificial drying or burning of the clay surface fin stt/a, thus forminga bed of a single brick burned or partially burned in place, is a usefulstep under certain conditions and with certain qualities of soil. Insome cases the burning or drying may be unnecessary. The compacted anddried clay bed is in itself a good roadway, has a considerableelasticity and great strength and hardness.

IVhen protected by the water-proof covering it is practicallyindestructible.

l. The improvement in the art of making roadways or pavements, whichconsists in bringing the general roadsurface to approximate grade,forming a convex body of clayey material thereon and compacting thesame, then kiln-drying or partially burning thecompacted surface by theapplication of heat, substantially as described.

2. The improvement in the method of building roads, which consists ingrading, rounding up a clayey bed for the substructure, thoroughlycompacting and drying the same, and applyingwater-procf wearing-surfacedirectly to the compacted clay bed.

3. The improvement in the art of road,- making, which consists ingrading, rounding a clay body for a substructure, compacting the same toextreme hardness, drying the surface by the artificial application ofheat, and covering the same with Separate layers of water-proofmaterial.

4. The artificial structure for roads, consisting of a compactedclay-body with convex sur face, said surface being burned in situ intoan integral brick-like substance, substantially as set forth anddescribed.

In testimony whereof I ailix my signature in presence of two witnesses.

PATRICK GRIFFIN.

Witnesses:

PHILIP MAURO, W. A. BARTLETT.

